WO2024118322A1 - Active rotating control device methodology and system - Google Patents

Abstract

A technique facilitates managed pressure drilling of a borehole. The technique utilizes a seal rotating system for managing pressure during a drilling operation. The seal rotating system has an elastomeric seal element which is rotatably mounted in the seal rotating system. When a drilling operation is to be performed, the seal rotating system may be deployed down into a rotating control device housing such that the elastomeric seal element is disposed within a packer, e.g. an elastomeric packer, which is rotatably mounted in the rotating control device housing. An actuator may be used to provide a controlled squeeze on the packer, thereby exerting an inward squeeze on the elastomeric seal element so as to maintain a suitable seal with a drill string extending therethrough. The seal rotating system may also include a load transfer member positioned to absorb loading due to wellbore pressure, thus reducing bearing loading.

Description

ACTIVE ROTATING CONTROL DEVICE METHODOLOGY

AND SYSTEM

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present document is based on and claims priority to U.S. Provisional Patent Application No. 63/385,828, filed December 2, 2022, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] In many oil and gas well applications, a rotating control device is used to contain and isolate pressure in the wellbore annulus while rotary drilling so as to enable managed pressure drilling. The rotating control device effectively creates a dynamic seal on the drill pipe during a drilling operation. Some types of rotating control devices utilize passive sealing in which a seal is created by a pre-formed elastomer having a slightly smaller opening than the circumference of the drill pipe. When the drill pipe is passed through the seal, the elastomer is squeezed against the drill pipe to create an initial seal. As well pressure increases, the elastomer seal may be squeezed harder to help continue sealing. However, if the sealing squeeze is not sufficient to maintain the seal, there is no way to increase the sealing force and thus the rotating control device fails to function properly.

[0003] Other types of rotating control devices utilize active sealing. The active sealing approach also employs an elastomer to create the seal against drill pipe. However, an external, controlled force is used to manipulate the amount of squeeze exerted by the elastomer against the drill pipe. If the seal between the elastomer and the drill pipe begins to wear and leak, the elastomer can be actively squeezed harder to re-energize the seal. However, such active systems are complex and the elastomer is subject to wear due to both the axial movement and the rotational movement of the drill pipe relative to the elastomer.

SUMMARY

[0004] In general, a methodology and system facilitate managed pressure drilling of a borehole, e.g. a wellbore. The technique utilizes a seal rotating system for managing pressure during a borehole drilling operation. The seal rotating system has an elastomeric seal element which is rotatably mounted in the seal rotating system. When a drilling operation is to be performed, the seal rotating system may be deployed down into a rotating control device housing such that the elastomeric seal element is disposed within a packer, e.g. an elastomeric packer, which is rotatably mounted in the rotating control device housing. An actuator may be used to provide a controlled squeeze on the packer which, in turn, exerts an inward squeeze on the elastomeric seal element so as to maintain a suitable seal with a drill string extending therethrough while rotating with the drill string. In some embodiments, the seal rotating system also may comprise a load transfer member positioned to absorb loading due to wellbore pressure, thus reducing bearing loading.

[0005] However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and: [0007] Figure 1 is a cross-sectional illustration of an example of a rotating control device housing combined with a packer for use in containing and isolating pressure in a borehole annulus while rotary drilling, according to an embodiment of the disclosure;

[0008] Figure 2 is a cross-sectional view of an example of a seal rotating system which may be deployed into the rotating control device housing, according to an embodiment of the disclosure;

[0009] Figure 3 is a cross-sectional view of an example of the seal rotating system deployed into the rotating control device housing, according to an embodiment of the disclosure;

[0010] Figure 4 is a cross-sectional view similar to that of Figure 3 but with a drill string extending therethrough, according to an embodiment of the disclosure; and

[0011] Figure 5 is a cross-sectional view of a portion of the seal rotating system deployed within the rotating control device housing, according to an embodiment of the disclosure.

DETAILED DESCRIPTION

[0012] In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

[0013] The disclosure herein generally involves a methodology and system which facilitate managed pressure drilling of a borehole, e.g. a wellbore. The technique provides a managed pressure drilling rotating control system able to operate at higher wellbore pressures while expanding the overall capability of the managed pressure drilling system. The approach also increases the reliability and longevity of the rotating control device system by reducing failures and repair costs.

[0014] Furthermore, the technique provides an active type system which uses actuator power, e.g. hydraulic actuator power, to create and modulate an elastomer seal on a drill string, e.g. on the drill pipe joints used to construct the drill string. With this approach, sealing elastomers rotate with the drill string rather than applying the conventional approach of using rotationally fixed elastomers. A rotating seal means that the only relative motion between drill string and seal is translation as the pipe sections of the drill string strip axially through the seal. As a result, substantially less friction and wear on the elastomer seal occurs as compared to conventional systems where the seal is rotationally static relative to the drill string.

[0015] In some embodiments, the methodology and system are constructed so as to reduce the end load on seal bearings. Bearings, e.g. roller bearings, may be used to enable the rotation of the elastomer as described above. Such bearings may have a limited load capacity, thus limiting their ability to absorb the entire loading due to wellbore pressure. As described in greater detail below, embodiments may use a load transfer member, e.g. a load transfer ring, positioned to transfer a substantial portion of the pressure load to a rotating control device housing and away from the bearings.

[0016] According to a specific embodiment, the technique utilizes a seal rotating system for managing pressure during a borehole drilling operation. The seal rotating system has an elastomeric seal element which is rotatably mounted in the seal rotating system. When a drilling operation is to be performed, the seal rotating system may be deployed down into a rotating control device housing such that the elastomeric seal element is disposed within a packer, e.g. an elastomeric packer, which is rotatably mounted in the rotating control device housing. An actuator may be used to provide a controlled squeeze on the packer which, in turn, exerts an inward squeeze on the elastomeric seal element so as to maintain a suitable seal with a drill string extending therethrough. In some embodiments, the seal rotating system also may comprise the load transfer member positioned to absorb loading due to wellbore pressure, thus reducing bearing loading.

[0017] Referring generally to Figure 1, a system 20 for managed pressure drilling which contains and isolates pressure in a borehole annulus, e.g. a wellbore annulus, while rotary drilling is illustrated. In this example, the system 20 comprises a rotating control device 22 having a rotating control device housing 24 forming an internal longitudinal passage 26. In a variety of subsea applications or other deepwater applications, the rotating control device housing 24 may be positioned along a riser 28 extending between, for example, a seabed location and a surface facility. The seabed location is used for drilling a borehole 30, e.g. a wellbore, down into a subterranean formation. The rotating control device housing 24 may be constructed as a standalone unit connected to the riser 28 (or other structure) or it may be constructed as an integral part of the riser 28. It should be noted the rotating control device housing 24 may be positioned along other types of equipment for use in other types of drilling applications.

[0018] In the illustrated example, the rotating control device 22 also comprises a rotatable packer structure 32 and an actuator system 34. The rotatable packer structure 32 also has an internal longitudinal passage 36 which is positioned along the overall longitudinal passage 26. By way of example, the rotatable packer structure 32 comprises a packer 38, e.g. an elastomeric packer, which is trapped between a rotatable packer housing 40 and a rotatable packer piston 42. The packer housing 40 and the packer piston 42 are rotatably mounted within rotating control device housing 24 via a plurality of packer bearings 44, e.g. roller bearings.

[0019] In the example illustrated, the plurality of packer bearings 44 comprises upper packer bearings and lower packer bearings. The upper packer bearings 44 are positioned between the rotatable packer housing 40 and the rotating control device housing 24; and the lower packer bearings 44 are positioned between the rotatable packer piston 42 and the actuator system 34. In some embodiments, centralizing bushings 45 may be positioned between the packer housing 40 and the rotating control device housing 24.

[0020] The actuator system 34 may be constructed in various configurations and may be activated via various motive forces created hydraulically, electrically, or otherwise so as to create the desired actuation force. In the example illustrated, the actuator system 34 is structured as a hydraulic actuator system having an actuator piston 46 which may be moved linearly via hydraulic pressure applied within a cavity 48 formed between the rotating control device housing 24 and an internal stationary actuator structure 50. The actuator piston 46 is connected with a bearing platform 52 which acts against the lower bearings 44.

[0021] In the example illustrated in Figure 1, hydraulic actuating fluid is introduced via a hydraulic pump system (not shown) below the actuator piston 46. Sufficient hydraulic pressure forces the actuator piston 46 upwardly along cavity 48 which, in turn, forces bearing platform 52, the lower bearings 44, and the rotatable packer piston 42 upwardly. The upward motion squeezes elastomeric packer 38. Because the elastomeric packer 38 is constrained by packer housing 40 and packer piston 42, the packer 38 deforms inwardly into internal longitudinal passage 36.

[0022] The rotating control device housing 24 also may incorporate fastening mechanisms 54 for releasably securing a seal rotating system 56 when received in passage 36 (see Figures 2 and 3). In some embodiments, the fastening mechanisms 54 may be remotely controllable from a surface location. For example, the fastening mechanisms 54 may be hydraulically or electrically controlled and may comprise pins, pistons, threaded members, or other suitable mechanisms which may be moved into passage 26 so as to secure the seal rotating system 56 at the desired location along passage 26.

[0023] Referring generally to Figure 2, an example of the seal rotating system 56 is illustrated. In this embodiment, the seal rotating system 56 comprises an elastomeric seal element 58 coupled into a support shaft 60 having an upper shaft section 62 above the elastomeric seal element 58 and a lower shaft section 64 below the elastomeric seal element 58. The support shaft 60 and elastomeric seal element 58 are formed with an internal longitudinal passage 65 therethrough to accommodate movement of components through the riser 28. Elastomeric seal element 58 may be coupled to support shaft 60 via molding, fasteners, or other suitable attachment techniques. In this example, the elastomeric seal element 58 is rotatably mounted on seal rotating system bearings 66 via support shaft 60. By way of example, the seal rotating system bearings 66 may comprise upper bearings 66 mounted between upper shaft section 62 and a surrounding latching shoulder 68. The seal rotating system bearings 66 also may comprise lower bearings 66 mounted between lower shaft section 64 and a load transfer member 70, e.g. a load transfer ring.

[0024] Additionally, rotary seals 72 may be positioned between the load transfer member 70 and lower shaft section 64 to maintain a seal therebetween as the elastomeric seal element 58 and support shaft 60 rotate on bearings 66 relative to load transfer member 70. The rotary seals 72 may be held in place by a seal retention ring 74 or other suitable structure. Additionally, a static seal or seals 76 may be positioned around the exterior of load transfer member 70, e.g. load transfer ring 70, to maintain a seal between the stationary load transfer member 70 and the surrounding, stationary rotating control device housing 24.

[0025] The seal rotating system 56 may be deployed down through riser 28 via a suitable running tool and secured within rotating control device 22 via fastening mechanisms 54, as illustrated in Figure 3. For example, once the seal rotating system 56 is at a desired location such that elastomeric seal element 58 is disposed within elastomeric packer 38, the fastening mechanisms 54 may be actuated to engage, for example, latching shoulder 68 and load transfer member 70 via a load transfer member shoulder 78. If the seal rotating system 56 is to be retrieved to the surface, the fastening mechanisms 54 may be released to allow the suitable running tool (or other tool) to pull the seal rotating system 56 upwardly to the surface. [0026] Referring generally to Figure 4, system 20 is illustrated with a drill string 80 deployed down through longitudinal passage 26 and through the interior passage 65 of seal rotating system 56. Once the drill string 80 is moved through seal rotating system 56, the elastomeric seal element 58 may be actuated into sealing engagement with the exterior surface of drill string 80.

[0027] As described above, actuator system 34 may be operated by a hydraulic pump system (not shown) which introduces hydraulic actuating fluid below the actuator piston 46. Sufficient hydraulic pressure forces the actuator piston 46 upwardly along cavity 48 which, in turn, forces bearing platform 52, the lower bearings 44, and the rotatable packer piston 42 upwardly. The upward motion squeezes elastomeric packer 38 and because the elastomeric packer 38 is constrained by packer housing 40 and packer piston 42 it deforms inwardly.

[0028] This inward deformation of elastomeric packer 38 acts against elastomeric seal element 58 in a lateral direction, thus forcing the elastomeric seal element 58 into sealing engagement with drill string 80. If degradation of the elastomeric seal element 58 occurs over time due to the linear motion of drill string 80 through the elastomeric seal element 58, continued application of force via actuator system 34 serves to compensate for the degradation. In other words, the ability to continually modulate the force applied by actuator system 34 enables continued movement of the degraded elastomeric seal element 58 toward drill string 80, thus maintaining a seal with the drill string 80.

[0029] Once the elastomeric seal element 58 is forced into sealing engagement with the drill string 80, the friction causes both elastomeric seal element 58 and elastomeric packer 38 to rotate with the drill string 80 via seal rotating system bearings 66 and packer bearings 44, respectively. This reduces or eliminates rotationally induced degradation of elastomeric seal element 58 which would otherwise occur if the drill string 80 rotated within elastomeric seal element 58 while the elastomeric seal element 58 remained rotationally fixed. [0030] Referring generally to Figure 5, an illustration is provided to help show how load transfer member 70 serves to reduce loading on seal rotating system bearings 66 and thus also on packer bearings 44. In this example, the load transfer member 70 is in the form of a load transfer ring which is secured in a stationary position with respect to rotating control device housing 24 via fastening mechanisms 54. Without load transfer ring 70, the entire force due to wellbore pressure below seal rotating system 56 could potentially be directed against seal rotating system bearings 66.

[0031] As illustrated, the load transfer ring 70 is positioned to absorb load forces associated with a relatively large wellbore pressure area 82. These forces are directed through load transfer ring 70 to the corresponding fastening mechanisms 54, and thus to the solid, robust rotating control device housing 24. As a result, the support shaft 60, and thus the seal rotating system bearings 66, are only exposed to a reduced wellbore pressure area 84. This reduces the load forces that would otherwise be absorbed by seal rotating system bearings 66. The ability to reduce load forces acting on the bearings 66/44 further helps promote the reliability and longevity of the overall system 20.

[0032] Depending on the specific well operation and well equipment, the overall system 20 may be adjusted and various additional or alternate components may be utilized. For example, the features, size, and shape of the rotating control device housing 24 may be adjusted. Similarly, the features and components of the rotatable packer structure 32, the actuator system 34, and the seal rotating system 56 may be selected according to the parameters of a given drilling operation and/or associated equipment employed in the drilling operation.

[0033] For example, the packer 38 and the seal element 58 may be made from a variety of elastomeric materials or even other types of materials able to form a suitable seal. Similarly, the actuator system 34 may be a hydraulic actuator system, an electromechanical actuator system, or another suitable type of actuator system able to apply the desired force resulting in a satisfactory seal between seal element 58 and drill string 80. The rotating control device housing 24 may be formed as a single component or multiple components connected together by fasteners, threaded engagement, or other suitable connection mechanisms. Additionally, the components may be constructed for use in a variety of subsea applications and also other types of drilling applications.

[0034] Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

Claims

CLAIMS What is claimed is:

1. A method for managed pressure drilling of a wellbore, comprising: positioning a rotating control device housing along a riser; rotatably mounting a packer in the rotating control device housing; lowering a seal rotating system into the rotating control device housing until an elastomeric seal element of the seal rotating system is positioned within the packer; deploying a drill string through the seal rotating system; squeezing the packer until the packer sufficiently deforms to drive the elastomeric seal element into sealing engagement with the drill string; and allowing the packer and the elastomeric seal element to rotate with the drill string.

2. The method as recited in claim 1, wherein rotatably mounting comprises rotatably mounting the packer on packer bearings.

3. The method as recited in claim 2, wherein allowing comprises mounting the elastomeric seal element on seal rotating system bearings.

4. The method as recited in claim 3, further comprising providing the seal rotating system with a load transfer ring to absorb loading force due to wellbore pressure, thus reducing loading on the seal rotating system bearings.

5. The method as recited in claim 4, wherein squeezing comprises using a hydraulically actuated piston to squeeze the packer. The method as recited in claim 5, wherein mounting the elastomeric seal element on seal rotating system bearings comprises coupling the elastomeric seal element into a support shaft and rotatably mounting the support shaft via the seal rotating system bearings. The method as recited in claim 6, further comprising sealing the load transfer ring the support shaft and the rotating control device housing. The method as recited in claim 1, further comprising releasably coupling the seal rotating system into the rotating control device housing via a plurality of actuatable fastening mechanisms. The method as recited in claim 1, wherein squeezing comprises continually compensating for degradation of the elastomeric seal element to maintain a desired seal with the drill string. The method as recited in claim 1, further comprising retrieving the seal rotating system from the rotating control device housing following a drilling operation. A method, comprising: rotatably mounting an elastomeric packer in a rotating control device housing via packer bearings; providing a seal rotating system with an elastomeric seal element rotatably mounted on seal rotating system bearings; positioning the seal rotating system in the rotating control device housing such that the elastomeric seal element is located within the elastomeric packer; and coupling an actuator with the elastomeric packer to enable deformation of the elastomeric packer in a manner which squeezes the elastomeric seal element inwardly to a sealing position. The method as recited in claim 1 1, further comprising deploying a drill string through the seal rotating system; and subsequently actuating the actuator to cause the elastomeric seal element to seal against the drill string. The method as recited in claim 12, further comprising providing the seal rotating system with a load transfer member to absorb loading due to wellbore pressure, thus reducing loading on the seal rotating system bearings. The method as recited in claim 11, wherein coupling the actuator comprises coupling a hydraulic actuator with the elastomeric packer. The method as recited in claim 11, further comprising connecting the elastomeric seal element to a support shaft rotatably mounted in the seal rotating system via the seal rotating system bearings. A system, comprising: a seal rotating system for managing pressure during a wellbore drilling operation, the seal rotating system having an elastomeric seal element rotatably mounted in the seal rotating system via a support shaft rotatable on seal rotating system bearings, the elastomeric seal element being selectively squeezable for sealing engagement with a drill string extending therethrough, the sealing engagement enabling rotation of the elastomeric seal element with the drill string, the seal rotating system further comprising a load transfer member to absorb loading force due to wellbore pressure, thus reducing loading on the seal rotating system bearings. The system as recited in claim 16, further comprising a rotating control device housing; and an elastomeric packer rotatably mounted in the rotating control device housing, the seal rotating system being deployed through the elastomeric packer. The system as recited in claim 17, further comprising an actuator coupled with the elastomeric packer to enable squeezing of the elastomeric packer which, in turn, squeezes the elastomeric seal element so as to seal against the drill string. The system as recited in claim 18, wherein the actuator is a hydraulic actuator. The system as recited in claim 19, wherein the load transfer member is a load transfer ring sealably positioned between the rotating control device housing and the support shaft.